Athletic boot

ABSTRACT

An athletic boot especially suitable for the construction of cross-country ski boots and ice skate boots, particularly ice hockey skate boots in which an inner molded shell is formed of a stiff or rigid material for providing rigidity at selected locations and an outer shell is molded about the inner shell, with the outer shell comprised of a dissimilar material having generally flexible and preferably abrasion-resistant characteristics to provide flexibility at selected locations and also provide an exterior surface capable of resisting surface wear and abrasion. The invention is concerned with the boot construction.

United States Patent [1 1 [111 3,807,062

Spier Apr. 30, 1974 ATHLETIC BOOT Prima ExaminerPatrick D. Lawson l. M rt N Y k, NY. W [75] Inventor a m Spiel" ew or Attorney, Agent, or FirmBlum, Moscovitz, Friedman [73] Assignee: Karku-Sport AB, Helsinki, Finland & K l

[22] Filed: Mar. 5, 1973 21 Appl. No.: 337,779 [57] ABSTRACT An athletic boot especially suitable for the construc- 'fl Apphcauon Data tion of cross-country ski boots and ice skate boots, [63] Conmuanommpa" of particularly ice hockey skate boots in which an inner 1971 1718994 molded shell is formed of a stiff or rigid material for providing rigidity at selected locations and an outer I s s s s s I s s I s s 1 s I I I s 1 I I e s s s I s a s a I I I s I a s e a t u e e e I Q a Fleld of Search R, 2.5 flexible and p e y resistant a 6 R f teristics to provide flexibility at selected locations and [5 1 e erences also provide an exterior surface capable of resisting UNITED STATES PATENTS surface wear and abrasion. The invention is concerned 3,530,595 9/1970 Vogel 36/2.5 AL With the bOOt construction. 3,535,800 10/1970 Stohr 3,694,940 10/1972 Stohr 36/2.5 AL 13 Claims, 11 Drawing Flgures PATENTED APR 3 0 1974 SHEET 2 U ATHLETIC BOOT CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of applicants Application Ser. No. 108,705, filed Jan. 22, 1971, now US. Pat. No. 3,718,994, issued Mar. 6, 1973.

BACKGROUND OF THE INVENTION This invention relates generally to an improved boot construction utilizing the teachings and principles as more particularly set forth in my prior copending application. In recent years, a revolution has taken place in the athletic boot industry, wherein boots formerly constructed of leather have increasingly had plastic substituted for the leather, especially in the fabrication of the outer shell. The primary function of an athletic boot, including cross-country ski boots and ice skate boots, is to provide proper support for the foot of the wearer and especially a measure of lateral rigidity, so that movements of the foot and ankle of the wearer are transmitted without loss of motion through the boot to the ski on which the boot is mounted by means of a' binding or to the ice skate blade which is rigidly attached to the boot.

It is also a requirement of the athletic boot that it have sufficient flexibility to permit the boot to be opened so that the boot may be put on and taken off, to permit the boot to be flexed to close tightly about the foot of the wearer, and to permit a measure of flexibility in the forward direction to permit the wearer to flex his ankles while skiing or skating.

As discussed at length in my prior copending application, the stiffness and rigidity characteristics required for proper support contradict the flexing requirements, and prior to applicants basic invention, boot shells have been formed of material which strikes a balance between the requisite rigidity and flexibility. To attain rigidity with a somewhat flexible material, prior boots have required a substantial buildup of thickness at selected locations, making the boot unnecessarily heavy and bulky.

SUMMARY OF THE INVENTION Generally speaking, in accordance with the invention, an athletic boot is fabricated of inner and outer shell portions, preferably by the method of first molding the inner shell portion and thereafter molding the outer shell portion about the inner shell portion for providing means, in addition to any chemical interlock that may take place, to mechanically interlock the inner and outer shell portions.

By utilizing inner and outer shell portions, different materials may be selected having different stiffnesses, rigidity, flexibility and wear characteristics. The inner shell portion having greater rigidity is so arranged as to provide rigidity where required for the particular athletic activity for which the boot is to be used, while the outer shell portion, in addition to providing scuff and wear resistance, will impart a measure of flexibility as required for athletic boots of this type.

For a skate boot, rigidity is required along the sole of the foot, about the heel and about the ankle portion, while permitting considerable flexibility at the instep, so that the foot may bend forwardly at the ankle joint.

For a cross-country boot, rigidity is required along the sole of the foot and about the lower part of the heel, but a high degree of flexibility is required where the foot bends between the ball and the toes as required by the skiing techniques attendant cross-country skiing.

Accordingly, it is an object of this invention to provide an athletic boot of improved construction.

Another object of this invention is to provide an improved athletic boot formed of multiple shell elements having flexibility at preselected locations.

A further object of the invention is to provide a skate boot of improved construction.

Still another object of the invention is to provide a cross-country ski boot of improved construction.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which will be exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the invention, reference is had to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of a skate boot constructed in accordance with a preferred embodiment of the instant invention;

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is an elevational view of a cross-country ski boot constructed in accordance with a preferred embodiment of the instant invention and showing the boot in the preferred position for molding;

FIG. 6 is'a top plan view of the boot of FIG. 5;

FIG. 7 is a sectional view, at an enlarged scale, taken along line 77 of FIG. 6; A

FIG. 8 is a bottom plan view of the boot of FIG. 6;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 7;

FIG. 10 is a sectional view taken along line l010 of FIG. 7; and

FIG. 11 is a sectional view taken along line 111l of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A skate boot constructed in accordance with the instant invention is shown in FIGS. 1 through 4. The boot indicated generally at 20 has an inner shell 21 and an outer shell 22. The outer shell is formed of a generally flexible plastic material having good abrasionresistance characteristics. Polyurethane and DuPont Hytrel have been found as especially suitable for the outer shell. Also, polyethylene or an ionomer which may be lighter and less expensive than polyurethane are also satisfactory materials for the outer shell 22. The inner shell 21 must be formed of a relatively rigid plastic material to impart strength, stiffness and rigidity to the boot. Materials such as expanded or nonexpanded acrylonitrile-butadiene-styrene (ABS) has proven especially satisfactory. Other materials may be acceptable, such as expanded polyurethane or expanded or nonexpanded polystyrene or expanded polypropylene. Scuff resistance is not a necessary characteristic of inner shell 21, as the inner shell is substantially completely protected against exterior abrasion by outer shell 22.

Inner shell 21 is formed with a toe box 23, sole 24, heel 25, back 26 and ankle-covering portions 27. When viewed in elevation, as best seen in FIG. 2, heel 25 does not extend to ankle-covering portions 27, thereby providing a cutout 28 on each side of inner shell 21, whereby the heel 25 is joined to ankle-covering portions 27 only through back 26. It will be readily understood that the cutout 28 eliminates the rigidity which would otherwise limit flexing of the ankle with respect to the foot in the forward direction at the ankle joint. Such flexing is required for skating by both hockey and figure skaters, although the boot depicted in FIGS. 1 through 4 is especially designed to be used as a hockey skate boot.

Inner shell 21 is formed with a plurality of apertures 29 therethrough, with the apertures being in the form of a truncated cone having the small end positioned to the exterior of inner shell 21 and the large end positioned to the interior of inner shell 21. Such apertures 29 will be seen along sole 24, heel 25 and anklecovering portions 27. Such apertures provide a mechanical interlock between the inner and outer shells, as will hereafter be apparent.

Outer shell 22 forms a complete boot and has a toe box 31, sole 32, vamps 33, heel 34, ankle and leg encircling portions 35 and flaps 36, by which the outer shell 22 may be closed about the foot of the wearer. Flaps 36 are shown as including eyelets 37, through which the boot may be laced in the known manner. In order to aid in closure of the outer shell about the boot of the wearer, an intermediate section 38 of lesser thickness is provided between flaps 36 and the main body of outer shell 22. Thinned sections 38 impart increased flexibility, so that the flaps can be more easily bent over the instep of the foot as the boot is being laced.

As aforenoted, inner shell 21 is preferably first formed by injection molding about a last or form (not shown). Outer shell 22 is thereafter formed, preferably by injection molding, about the previously formed inner shell 21. Because many of the preferred inner and outer shell materials do not readily form a chemical bond therebetween, the apertures 29 have been provided, and as can be seen from the sectional views of FIGS. 2 and 4, the material of the outer shell flows into the apertures 29, thereby forming a mechanical bond between the inner and outer shells. The mechanical bond substantially eliminates relative movement between the inner and outer shells to prevent abrasion and maintain proper positioning between the two shells.

For greater comfort and improved fit, it is contemplated that a liner formed of cloth, leather and/or spongy materials will be inserted in the finished boots, but as such finishing materials form no part of the instant invention, they have not been shown for either type of boot.

The same inventive concept is incorporated in the cross-country boot shown in FIGS. through 11. A cross-country boot need not be as high as a skate boot and thus normally does not extend above or to the wearers ankle bones. However, torque resistance in a lateral direction is an important function of a crosscountry boot, so that the forward drive imparted by the skier will be transferred without lost motion through the boot and binding to the ski. Edge control is also an important factor in cross-country skiing, whereby the lateral rigidity imparted by the construction of the instant invention especially adapts itself for a crosscountry boot.

In a cross-country boot, an inner shell 41 and an outer shell 42 are provided. Materials suitable for the inner shell 41 are similar to the materials described in connection with inner shell 21 of the skate boot, and materials suitable for outer shell 42 are similar to the materials described in connection with outer shell 22 of the skate boot. Inner shell 41 has a toe portion 43 with a projecting lip 44, a sole 45 and a heel 46. In the area where the foot flexes forward of the ball, sole 45 is corrugated as indicated at 47. The corrugations 47 provide a plurality of thinned sections, thereby imparting considerable flexibility to the sole across its lateral extent, to thereby allow, with an otherwise generally rigid material, the substantial flexing of the sole required for cross-country skiing, as is well known to those who partake of the sport.

Outer shell 42 is provided with a toe box 51, a sole 52 which underlies the boot and also surrounds projecting lip 44, vamps 53, a heel 54, a back 55 and ankleencircling portions 56 which normally extend to a level below the ankle bones of the wearer. Outer shell 42 is also provided with a flap 57 by which the boot may be closed and latched about the foot of the wearer by means of a suitable buckle 58. Also, a snow cuff 59 formed of any suitable stretchable fabric or material may be stitched or otherwise secured at the ankle opening for a close fit about the wearers foot to minimize the entry of snow into the boot.

The flexing portion 'of the boot in the area forward and above the ball of the foot and above the sole is molded with an accordion effect, as indicated at 61, in order to allow the boot to be flexed the substantial degree required for a boot of this type. It has been found preferable to mold the outer shell 42 in a position such as is indicated in FIG. 5, with the heel raised from the horizontal by the angle 9. An angle 0 of about 22% has been found effective so that the boot can readily flex 22% in either direction from the molded position to provide flexing from the horizontal by an amount of 45. If a greater total degree of flexibility is desired, the boot could be molded at a greater angle to the horizontal. As the boot when flexing will require a greater degree of accordion effect at points most distant from the bend line along the sole, it can be seen from FIGS. 6 and 7 that the accordion effect decreases toward the sole and increases as the distance from the sole increases.

A cross-country ski boot will normally be provided with a heel 54, as best seen in FIG. 11, and the heel may also have a slot 62 which cooperates with a guide as part of the binding on the ski to aid in alignment of the boot on the ski when the boot is in the lowered position. In view of the depth of heel 54, it may be desirable or necessary to insert a platform 63 in the heel so that the heel of the foot is properly positioned within the boot. Platform 63 can be of any suitable material and could be molded as part of the inner shell 41, but this would unnecessarily complicate the molding process.

Platform 63 is not considered to be part of the present invention.

As described in connection with the skate boot, it is likewise desirable with respect to the cross-country boot to provide a mechanical interlock between the inner and outer shells. In the embodiment of FIGS. 5 through 11, projections 64 are molded as an integral part of inner shell 41 when the inner shell is initially molded. During the molding of outer shell 42 about inner shell 41, projections 64 will extend through the outer shell, as best seen in FIGS 8, 9 and 11, to thereby provide a mechanical interlock. A mechanical interlock on opposite sides of the accordion portions 61 and the corrugations 47 is especially important in view of the substantial sheer forces occurring between the inner and outer shells during the considerable flexing of the boot during use.

Applicants basic invention has been embodied in the prior copending application, and a preferred embodiment has been described therein as same relates to a ski boot of the type used for alpine skiing. The principles of invention have been further developed in the instant application, wherein there is disclosed embodiments of athletic boots especially suitable as ice skate and crosscountry ski boots.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and since certain changes may be made in the above article without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

What is claimed is:

1. An athletic boot comprising a molded inner shell of a first material and a molded outer shell of a second material bonded to said inner shell, said inner shell defining at least a sole, a heel, a back and ankle covering portions, said ankle covering portions being joined to said heel only along said back whereby to permit flexing of said inner shell along the longitudinal axis thereof below said ankle covering portions, said inner shell being formed of a generally rigid plastic material, said outer shell defining a sole, a toe box, vamps, a heel and ankle and leg encircling portions extending above said ankle covering portions of said inner shell, said outer shell being formed of a generally flexible plastic material.

2. An athletic boot as claimed in claim 1 including means cooperating between said inner and outer shells for effecting a mechanical interlock between said inner and outer shells.

3. An athletic boot as claimed in claim 2 wherein said mechanical interlock means includes a plurality of apertures in said inner shell and projections on said outer shell extending into said apertures.

4. An athletic boot as claimed in claim 3 wherein at least some of said apertures are in the form of truncated cones having the smaller end thereof facing said outer shell and wherein said projections closely follow the configuration of said apertures.

5. An athletic boot as claimed in claim 1 wherein said outer shell further includes flaps extending outwardly of said vamps whereby to effect closing of said boot about the foot of a wearer.

6. An athletic boot as claimed in claim 5 wherein each flap extends from its associated vamp along a thinned section of outer shell material.

7. An athletic boot comprising a molded inner shell of a first material and a molded outer shell of a second material bonded to said inner shell, said inner shell defining at least a sole and a heel, said inner shell being formed of generally rigid plastic material, said sole being constructed and arranged to permit flexing thereof in the area forward of the area adapted for receiving the ball of the foot, said outer shell defining a sole, a toe box, vamps, a heel, a back and ankle encircling portions, said outer shell being formed of a generally flexible plastic material.

8. An athletic boot as claimed in claim 7 including means cooperating between said inner and outer shells for effecting a mechanical interlock between said inner and outer shells.

9. An athletic boot as claimed in claim 8 wherein said mechanical interlock means includes a plurality of projections on said inner shell extending into said outer shell.

10. An athletic boot as claimed in claim 7 wherein said outer shell is constructed and arranged to permit flexing thereof in the area forward and above the area adapted for receiving the ball of the foot.

11. An athletic boot as claimed in claim 10 wherein said outer shell construction includes accordian-like pleats in and above the last named area.

12. A athletic boot as claimed in claim 7 wherein said inner shell construction includes means for defining a plurality of thinned sections in the area forward of the area adapted for receiving the ball of the foot.

13. An athletic boot as claimed in claim 12 wherein said last named means is formed as a series of corrugations. 

1. An athletic boot comprising a molded inner shell of a first material and a molded outer shell of a second material bonded to said inner shell, said inner shell defining at least a sole, a heel, a back and ankle covering portions, said ankle covering portions being joined to said heel only along said back whereby to permit flexing of said inner shell along the longitudinal axis thereof below said ankle covering portions, said inner shell being formed of a generally rigid plastic material, said outer shell defining a sole, a toe box, vamps, a heel and ankle and leg encircling portions extending above said ankle covering portions of said inner shell, said outer shell being formed of a generally flexible plastic material.
 2. An athletic boot as claimed in claim 1 including means cooperating between said inner and outer shells for effecting a mechanical interlock between said inner and outer shells.
 3. An athletic boot as claimed in claim 2 wherein said mechanical interlock means includes a plurality of apertures in said inner shell and projections on said outer shell extending into said apertures.
 4. An athletic boot as claimed in claim 3 wherein at least some of said apertures are in the form of truncated cones having the smaller end thereof facing said outer shell and wherein said projections closely follow the configuration of said apertures.
 5. An athletic boot as claimed in claim 1 wherein said outer shell further includes flaps extending outwardly of said vamps whereby to effect closing of said boot about the foot of a wearer.
 6. An athletic boot as claimed in claim 5 wherein each flap extends from its associated vamp along a thinned section of outer shell material.
 7. An athletic boot comprising a molded inner shell of a first material and a molded outer shell of a second material bonded to said inner shell, said inner shell defining at least a sole and a heel, said inner shell being formed of generally rigid plastic material, said sole being constructed and arranged to permit flexing thereof in the area forward of the area adapted for receiving the ball of the foot, said outer shell defining a sole, a toe box, vamps, a heel, a back and ankle encircling portions, said outer shell being formed of a generally flexible plastic material.
 8. An athletic boot as claimed in claim 7 including means cooperating between said inner and outer shells for effecting a mechanical interlock between said inner and outer shells.
 9. An athletic boot as claimed in claim 8 wherein said mechanical interlock means includes a plurality of projections on said inner shell extending into said outer shell.
 10. An athletic boot as claimed in claim 7 wherein said outer shell is constructed and arranged to permit flexing thereof in the area forward and above the area adapted for receiving the ball of the foot.
 11. An athletic boot as claimed in claim 10 wherein said outer shell construction includes accordian-like pleats in and above the last named area.
 12. A athletic boot as claimed in claim 7 wherein said inner shell construction includes means for defining a plurality of thinned sections in the area forward of the area adapted for receiving the ball of the foot.
 13. An athletic boot as claimed in claim 12 wherein said last named means is formed as a series of corrugations. 